Centralizer for drill steels



' Sept.23, 1930. J. F. MOCK CENTRALIZER'FOR DRILL STEELS Filed Nov. 2,1927 Patented Sept. 23, 1930 -U IT D.- TATES PATENT OFF ICE JOHN 1?.HUGE, F PHILLIPSBUQRGVNEW JERSEY, ASSIGNOR .TO INeEBsoLL-Rnin coinrAnY,OF .IERSEY CITY, NEW JERSEY, A CORPORATION \OF-NEW, JERSEY HG ENTRALIZER is c g c c g Application filed November This invention relates torock drills, but more particularly to a, centralizeradapted to be'supportedfby afrock drill'shell and V ,forming a bearing for jthe freeend of the jOjneob'je'ct of theinvention' is to maintain the cutting bitof the drill steel in axial alignment with the rock drill, p'articularlywhen starting a new drill hole in a rock face.

Another object of the' invention is to simplify the constructionandvreduce the cost of maintenance of centralizers of this type.

/ Other objects will appear hereinafter and to all of these endsthein'vention consists of the combination of" elements and arrangementsof parts substantially as hereinafter described and claimed andillustrated in theaccompanying drawings, in which Figurel is anelevation of the front end of aro c'kdrilland its shell,illustrating-the manner in which the centralizer supports and guides thedrill steel, Figure 2 is a transverse view taken through Figure 1 on theline 2-2 l-ookingin the direction indicated by the arrows, and

Figure 3 is an enlarged side elevation of the centralizer.

Referring more particularly to the drawings, represents a shell ofanysuitable type havinga conical projection B whereby the shellinayfbesecured to a lcolumn or other 1 suitable'support for holding theshell in fixed "position with respect to the working surface,

such as the rock U.

In the present instance," only the front end of a rock drill front headDis shown in the drawings for the'sake of simplicity of illustration,but it is to be understood that other elements (nbtshown) of therockdrill may cooperate slidably with guideways 'E of the shell'A in a wellknown manner. A working' implement F illustrated in this "instance as a.drill steel-extends with its rearward "end into the front head D toreceive the blows'of a reciprocatory hammer pistonfnot shown) of thedrill.

In certaindrilling operations, it is at times found diflicult tomaintain the drill bit in,

axial alignment with the rock drill whereby the drill steel is beingactuated, particularly oitnnrtn a, 1927.1 sria ir 30,552,

inclined position;

of usage wear is caused in'the chuck parts of the rock drill and asafresult thebit'end of the drill steel tends to decline-from the whenthe rock drill lies in a horizontal or an After a certaiIY-periodaxis ofthe rock'drill. Such declination of.

conditions aref"not detected until arcertain depth has been drilled oruntil drillf'st'eels of greater length have been'substitu'ted" for thestarting steel. This condition requiresa'n in terruption in'the drillingoperation to adjust the rock cide with the course of the drill hole,otherdrill to, a position which will coinwise the drill steel willbindinlthe drill hole and will greatly hinder the efic'ient operation ofboth the percussiveeleinentand the rotation mechanism. Moreover, if thedrill steel is not maintained substantially coaxial with the rock drillit will be difiioult tO maint-ain thegauge of-the drill bit and thedrill steel will require more frequent sharpeningythan would be "thecase were the drill steel heldin" 7 axial alignment with of the rockdrill. v I The-present invention aims to eliminatethe foregoingdescribed unfavorable features is .disposedaboutthe drill steel F 'toform a bearing therefor near the ffon'tend 'of' the and to this end acentralizer designated by G the chuckmechanism drill steel. Thecentralizer G'comprisesa- 7 pair ofiarms H and Jboth of which'liave 1 ateral extensions Kat {their lowermost. ends to extend slidably into theguideways of the shellA. f M

In the inner or adjacent surfaces L of the arms Hand: J are I formedsemi-circular l grooves "O for the reception of bushings P.

The bushingsP are in this instance also of semi-circular form'and areadapted to contact with each othenwhenin the operative position aboutthedrill steel The bushj the arms tensions K ings P seat loosely in thegrooves 0 so that the said bushings and the arms are capable of somerelative rotative movement.

Suitable means are provided for maintain-' ing the bushings P in thearms H and J. These means in the present instance consist of laterallugs Q, which extend through trans verse apertures R in the arms H and JThe lateral lugs Q, free ends be'yondthe apertures-R to enable the freeends of said lugs to be upset to form projecting portions S which maycooperate with the side of the arms H and J to prevent accidentalwithdrawal of the bushings from the said arms. V p To the end that acertain pivotal movement may be obtained between the bushings P and Hand J the apertures are preferably of somewhat larger cross sectionalareathan the lugs Q. In this way the bushings P willbe free to adjustthemselves to the .sameoperative position irrespective of the width ofthe shell in which thecentralizer m y b disposal. r i r,

Means are provided for drawing together the uppermost ends T and U ofthe arms H and J and thus also to force the lateral exinto and maintainthem in .en-

. gagement with the guideways E of the shell These means in thepresentinstanceconsist of aT-shape'd latch in theform of a bolt V which.extends through an aperture Win the arm Hand through a slot X in'the armJ.

The bar or headY of the bolt V preferably bears against the sideof thearm H and a nut Z is threaded on the opposite end of the bolt I V tobear against theside of the arm J.

In .assembling thecentralizer a bushing P may be placed in each of thearms H and J and the projecting endsof the'lugs Qfmay then be upset inthe mannerdescribed. After the bolt V'has been placed in the arms the Vcentralizer will be in readiness to be disposed about the drill steel E.This may be accomtween the arms or,

pli shed by either inserting the drill steel bearms; 7

After the centralizer has been disposed in the guideways E of the shellthe nut Z may be tightened "inlthe direction necessary to both move thelateral extensions K outwardly and force them into the guideways E andalso to force theadjacent surfaces of the bushings P firmly into contactwith each other. By turning the nut Z down tightly against the arm .Jthe lateral extensions K maybe forced into the guideways E to such anextent that the centralizer may only be preferably extend with their,

I if the drill steel be of the type which is equipped with a collar orlugs or other equivalent means for preventing its ejection from thefront head, the nut Z may removed by again relieving the pressure of thenut Z. Ordinarily however, it is desirable that only' sufficientfriction should exist between the guideways E and the lateral extensionsK to prevent the centralizer from being shaken out of the shell by thevibrations and shocks incident to drilling. When so adjusted thecentralizer may be readily displaced by the front end of the front headD as said front head approaches the front end of the shell A. Thecentralizer will be gradually pushed out of the guideways E and may thenbe removed from the vicinity of" the drillhole without interrupting thedrilling. j

I claim; I

l. A centralizer, for drill steels, comprising a pair of arms forming aguidefora drill steel, means integral with one end of the arms adaptedto cooperate slidably with the guideways of a rock drill shell,and'means acting on the other endsof the arms to draw the last mentionedends together for pressing the first said means laterally outward intoen V gagement withsu'ch guideways. "'9

2. A centralizer for drill steels, comprising a pair of arms, bushingsin the arms adapted to encircle adrill steel and seating responding endsof h alms to cooperate' slidably with theguideways of afrock drillshell, and means acting on the other ends of the arms for pressingthebushings into contact with each other and for forcing the lat eralextensions into engagement with such '10!) guideways. w v V V 3, Acentralizer for drill steels, comprising a pair of arms havingtransverse apertures, semi-circular bushings in. adjacent sides of thearms forming a bearing for a drill steel, lateral lugs on the bushingsextending loosely through the apertures, upset portions on the lugscooperating with the arms to maintain the bushings in the arms, lateralextensions on corresponding ends of 1 the arms to extend into theguideways of a rock drill shell, and means including a bolt V tionalengagement with such guideways. be. inserted between the surfaces Lofthe 4 A centralizer for drill steels, comprising a pair of armshavingtransverse aper-, tures, semi-circular bushings in adjacent sidesof. the arms forming a bearing fora drill steel, lateral lugs on thebushings extending through the apertures, said lugs being of smallercross-sectional area than the apertures to permit limited rotation ofthe bushings with respect to the arms, upset portions on the free endsof the lugs cooperating with the arms to .maintain the bushings in thearms, lateral extensions on correspond-w ing ends of the arms to extendinto the guide Ways of a rock drill shell, and means including a boltand nut acting on the other ends of the arms for pressing adjacentfacesof the bushings firmly into contact with each other and formaintaining the lateral extensions in frictional engagement with suchguideways;

In testimony whereof I have signed this specification. JOHN F. MOOK.

